1. Field of the Invention
This invention is directed to an improved, completely portable, self-contained hydraulically actuated clamp, especially a portable, hand-held wrench. The hydraulically actuated jaws apply a greater clamping force to an object such as a nut or bolt. It is especially useful in cramped locations where it is difficult to reach with the hands to close or open a manually adjustable wrench.
2. Description of Related Art
The Mar. 9, 1964 issue of Electrical World, page 70 includes an advertisement showing several types of Hydraulic Cutters being marketed by H. K. Porter, Inc. of Somerville, Mass. The POWER Hydraulic Cutters shown there include hoses connected to a remotely located, hydraulic power unit. Also shown in the same reference is a HAND Hydraulic Cutter. This unit shows a hand-held cutter tool which is connected by a hydraulic hose to a hand-operated hydraulic pump which appears to sit on the floor when the unit is in use.
U.S. Pat. Nos. 3,561,117 and 4,369,576 describe hydraulic cutting tools similar to that shown in the Electrical World, in which a pair of hydraulic fluid hoses connect the cutters to a remotely located hydraulic pump means.
U.S. Pat. Nos. 4,141,261 and 4,339,968 are both directed to hydraulic wrench systems. U.S. Pat. No. 4,141,261 describes a completely self-contained hydraulic wrench system, but the system merely provides torque to a socket 120 of fixed size. There is no clamping action by the socket against the nut to be loosened or tightened.
U.S. Pat. No. 4,339,968 is also directed to a hydraulic wrench. However, this system appears to have an external, hydraulic fluid source which connects to the tool by means of a hydraulic hose. The hydraulically driven tool is a removal socket of fixed size, so there is no clamping action by the tool on the nut or bolt.
A self-contained, hand-operated hydraulic cutter is shown in Cooper Industries, Cooper Tools Division 1987 Industrial Tools Catalog No. 55341. This tool contains a two stage hydraulic pump in the forward end of the operating handle, immediately adjacent the bolt cutter head. The object is to develop high cutting torque with less effort. It appears that the hydraulic pump must be operated with both hands, and that both cutting jaws are connected to, and operated together, by the hydraulic system.
None of the above patents or references describe a self-contained, hand-held hydraulic clamp such as applicant's invention, which has a stationary jaw and a complementary hydraulically operated jaw which can be clamped firmly on a pipe, nut, or a bolthead so that mechanical torque can be applied through the stationary jaw handle without slipping, or without applying excessive pressure against the nut or bolthead which might cause it to deform (bolthead) or freeze in place (nut).